package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long id, boolean isFollow) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        //判断是关注还是取关
        if (isFollow){
            //关注
            Follow follow=new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(id);
            boolean isSuccess = save(follow);
            if (isSuccess){
                stringRedisTemplate.opsForSet().add(key,id.toString());
            }
        }else {
            //取关
            boolean isSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", id));
            if (isSuccess){
                stringRedisTemplate.opsForSet().remove(key,id.byteValue());
            }
        }

        return Result.ok();
    }

    @Override
    public Result isFollow(Long id) {
        //获取登录用户id
        Long userId = UserHolder.getUser().getId();
        Integer count = query()
                .eq("user_id", userId).eq("follow_user_id", id).count();

        return Result.ok(count>0);
    }

    /**
     * 查看共同关注
     * @param id
     * @return
     */
    @Override
    public Result followCommons(Long id) {
        //获取登录用户id
        Long userId = UserHolder.getUser().getId();
        //获取用户保存到Redis的key
        String key1= "follows:"+id;
        String key2= "follows:"+userId;
        Set<String> intersect = stringRedisTemplate
                .opsForSet().intersect(key1, key2);
        if (intersect==null||intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = intersect.stream()
                .map(Long::valueOf)
                .collect(Collectors.toList());
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }
}
